Ring & Split Core CT

Just guessing from a mechanical point of view. Ring type the conductor passes through (you must remove the conductor to replace it) and split clamps around the conductor (you don't need to remove the conductor to replace it). I have seen some split CTs for test instruments, not permanent CTs (a clamp on ammeter is a split CT of sorts). The caution I have on split CTs is to kill the circuit before installing as a friend just blew up his hand held clamp on meter clamping in a HV line; it was an 'open' CT for a moment and it blew up in his hand.

Normally, the CT is identified by the primary current rating, secondary current rating, and its class, in addition to the other data (e.g. rated voltage, lightning impulses, etc.).

The term Class X, indicates that the current transformer has low leakage reactance, for which knowledge of its secondary excitation characteristics, secondary winding resistance, secondary burden resistance and turns ratio is sufficient to assess its performance in relation to the protective relay. This type is commonly used in differential protection applications.

Vk, stands for the rated Knee Voltage of the current transformer, which when increased by 10% causes the exciting current to increase by no more than 50%. Vk is the minimum e.m.f. applied to the secondary of the CT.

Rct, is the secondary winding DC resistance of the current transformer corrected to 75C.

Im, is the magnetizing current.

I hope the above clarifies some...

Hi Guest!

I have the different Data on CTs:

Dump = The VA to which minimum loaded.

R-CT = the recommended Termination of CT

Note:

Un-loaded CT may be dangerous as VHV Peeks aegenerated.

Regards.

Regards!

I add:

there is a 3rd type not commonly known by most of the people in field:

"Current Probe" have continuous turns on a straight Insulator material rod.

Clamp-on & Ring CTs measure Current through a single conductor, but the Probe-Type measures without breaking Electrical Circuit nor need to Split magnetic Circuit.

But inserted between 2 Conductors.

It has the advantage of sensitivity as the flux around both the conductors add in-side 2 conductors [for Probe].